The 3rd Generation Partnership Project (3GPP) provides system specifications for third-generation (3G) mobile networks including General Packet Radio Service (GPRS) networks and Long Term Evolution (LTE) networks. LTE is also referred to as evolved packet system (EPS). GPRS networks and LTE networks provide session management and transport for Internet Protocol (IP) packet services. A policy control and charging (PCC) architecture allows operators to perform service-based Quality of Service (QoS) policy and flow-based charging control.
The 3GPP generally describes the components of the GPRS networks and LTE networks and their interactions with each other in a number of technical specifications. Specifically, 3GPP TS 23.203, 3GPP TS 29.212, 3GPP TS 29.213, and 3GPP TS 29.214 describe the Policy and Charging Rules Function (PCRF), Policy and Charging Enforcement Function (PCEF), and Bearer Binding and Event Reporting Function (BBERF). These specifications further provide some guidance as to how these elements interact in order to provide reliable data services and charge subscribers for use thereof. The 3GPP specification allows the Policy and Charging Control (PCC) architecture to interwork with older generation networks (e.g., General Packet Radio Service (GPRS)) as well as newer LTE networks. For example, 3GPP TS 29.212 and 3GPP TS 29.214 provide some guidance on the establishment of an application session upon receipt of an application request from an Application Function (AF) in the form of an AA-Request (AAR) message or from a Packet Data Network Gateway (PGW) in the form of a Credit Control Request (CCR) message. The standards specify that the PCRF is responsible for receiving new service requests, creating new PCC rules commensurate with such requests, and providing these new PCC rules to a Policy and Charging Enforcement Function (PCEF) for installation. The 3GPP standards also define the format of service request messages and PCC rules.
GPRS and EPS differ in how bearer management is handled. In GPRS bearer management and bearer negotiation is done explicitly to manage flows. In EPS, bearer management is handled invisibly. Also, in EPS a new attribute value pair (AVP) is introduced to specifically talk to the default bearer “Default-EPS-Bearer-QoS” and it defines the QoS information for the EPS default bearer and provides for QoS Class Identifier (QCI) and Allocation Retention Priority (ARP) information, which Indicates a priority for accepting or rejecting a bearer establishment or modification request. In the GPRS specification, there is no concept of a default bearer.
Therefore, a means of managing default bearers in a GPRS network is highly desirable.